This invention relates to power operation of a pivotal vehicle closure element and more particularly to power operation thereof by means of a motor driven four-bar hinge articulation support.
Power operation of vehicle closure elements such as doors, hoods, liftgates, tailgates and deck lids is, in principle, known in the prior art. Convenience and ergonomic related benefits associated with providing power operation of closure elements are readily apparent. A growing marketplace trend toward preferring such convenience, and in certain cases, necessary features exist. With respect to hoods and deck lids, certain smaller size passenger vehicles are provided with four-bar hinge articulated support in order to provide a special travel path of the movable hood or deck lid during its motion between fully open and fully closed position in order to accommodate clearance of various body obstructions. Such four-bar hinge articulation also increases the angular range of pivotable travel of the closure element so that the same is out of the way of the personnel gaining access to or from the vehicle compartment closed by the element. In some vehicles the hinge is located on the weather side of the compartment closure weather seal, an adverse environment for locating an electromechanical drive unit for powering the flange. Therefore, a need continues to exist for relatively non-complex, weatherproof, compact, competitive and reliable means of power operation for a four-bar hinge articulation of the vehicle closure element which also readily permits manual actuation thereof in the normal state with the power drive de-energized.
Accordingly, among the objects of the invention are to provide an improved four-bar hinge articulation of a pivotable vehicle closure element which is capable of power opening and closing the closure element by remote control actuation, that is essentially invisible to the customer or vehicle user with respect to the power drive components of the system, that can be overridden by manual force applied to open and close the closure element, that provides a compact power drive system for the four-bar hinge, that is capable of operation with standard obstacle detection software and which is rugged, compact, economical in construction and installation and in which the electrical components and drive system are shielded from exterior weather by mounting in a normally unused space within a weather sealed compartment of the vehicle.
In general, and by way of summary description and not by way of limitation, this invention accomplishes one or more of the foregoing objects by providing an improved four-bar hinge assembly for attaching a pivotable vehicle closure element to the vehicle body in which the control link of the four-bar linkage has its usual vehicle-mounted pivot pin replaced by the rotatably driven output shaft of a power drive mechanism. The output shaft is rigidly and directly coupled to the control link to impart swinging motion to the same to thereby power actuate the four-bar linkage in order to pivot the closure element for travel between open and closed positions. The four-bar linkage hinge elements are located in their usual position on the weather side of the vehicle body components. However, the pivot support/drive shaft extends through the vehicle sheet metal separating the weather side from the weather sealed compartment closed by the vehicle closure element so that all components of the electromagnetic drive system are mounted within the weather sealed and preferably normally unused compartment space of the vehicle accessed by the vehicle closure element. The power drive unit preferably comprises a completely encased gear reduction transmission driven by a conventional, reversible electric motor and associated electromagnetic clutch operable remotely via a control circuit of conventional construction. Preferably telescopic gas spring counterbalance elements are also provided to reduce power requirements and to enable manual operation when desired. Limit switches may be provided to de-energize the electric motor and electromagnetic clutch at the end limits of closure element travel, as well as to sense obstructions to travel to de-energize the system. The electromagnetic clutch disengages when de-energized so that the closure element can be moved manually in the event of power failure.